CN-122028652-A - Cross-dimension phase change device based on semi-metal material, preparation method, phase change induction method and application

CN122028652ACN 122028652 ACN122028652 ACN 122028652ACN-122028652-A

Abstract

The embodiment of the invention provides a cross-dimensional phase change device based on a semi-metal material, a preparation method, a phase change induction method and application, and belongs to the technical field of topological quantum devices. The trans-dimension phase change device comprises a SiO 2 /Si substrate, a semi-metal material layer which is positioned on the upper surface of the SiO 2 /Si substrate and has a two-dimensional ferroelectric phase in an initial state, and a metal electrode which is in electrical contact with the semi-metal material layer, wherein external electrical excitation enables the semi-metal material layer to generate a non-component and reversible trans-dimension structure phase change through the metal electrode, and a resistance hysteresis loop is formed by converting the two-dimensional ferroelectric phase into a three-dimensional topological T' phase and accompanying with abrupt change of a resistance state. The invention realizes the cross-dimension structure phase change between the semi-metallic material and other components and the reversible two-dimensional ferroelectric phase and the three-dimensional topological T' phase, and takes the dimension as the parameter for driving the topological phase change to increase the degree of freedom of topological physical property regulation.

Inventors

ZHENG SHOUJUN
LIANG QINGRONG
ZHOU JIADONG

Assignees

北京理工大学

Dates

Publication Date: 20260512
Application Date: 20251230

Claims (10)

1. A half-metal material-based cross-dimensional phase change device, the cross-dimensional phase change device comprising: A SiO 2 /Si substrate; The semi-metal material layer is positioned on the upper surface of the SiO 2 /Si substrate, and the initial state of the semi-metal material layer is a two-dimensional ferroelectric phase; A metal electrode in electrical contact with the semi-metal material layer, wherein The external electric excitation causes the semi-metal material layer to generate a phase change of a cross-dimensional structure with unchanged components and reversibility through the metal electrode, and the phase change is converted from the two-dimensional ferroelectric phase to a three-dimensional topological T' phase, and a resistance hysteresis loop is formed along with abrupt change of a resistance state.
2. The cross-dimensional phase-change device of claim 1, The semi-metallic material is any one of PtBi 2 、PdBi 2 and NiBi 2 or any combination thereof, The thickness of the semi-metal material layer is 1-100nm.
3. The cross-dimensional phase-change device of claim 2, The metal electrode is a Cr/Au composite electrode, wherein the thickness of a Cr layer is 3-10nm, and the thickness of an Au layer is 40-60nm; the structure of the metal electrode is a two-end cross bar structure, a Hall rod structure or a three-end structure integrated with the field effect transistor.
4. The cross-dimensional phase-change device of claim 2, The external electrical stimulus comprises a voltage sweep, a current sweep or a pulsed electrical stimulus, The external electrical stimulus induces a phase change of the trans-dimensional structure by joule heating effect, The critical temperature of the trans-dimensional structure phase transition is 600-700K.
5. The cross-dimensional phase-change device of any one of claims 1-4, When PtBi 2 is used as the semi-metallic material, the atomic mechanism of the cross-dimensional structural phase transition includes: the Bi-Bi-Pt-Pt-Bi-Bi six-membered ring in the two-dimensional ferroelectric phase of the PtBi 2 material layer is deformed in-plane; the Pt atomic layer splits, wherein a portion of the Pt atoms migrate vertically downward and through the bottom Bi atomic layer to migrate to the van der waals gap; And forming a covalent bond between the migrated Pt atoms and Bi atoms at the top of the adjacent PtBi 2 material layer, and reconstructing a Bi-Pt-Bi three-layer structure into a Bi-Pt-Bi-Pt four-layer structure to form the structural reconstruction from the two-dimensional ferroelectric phase to the three-dimensional topological T' phase.
6. The cross-dimensional phase-change device of claim 5, In the PtBi 2 material layer, one part of the region is a two-dimensional ferroelectric phase, the other part of the region is a three-dimensional topological T' phase, a heterojunction in which the two-dimensional phase and the three-dimensional phase coexist is formed, and an interface topological boundary state is formed at the junction of the region so as to realize quantum transmission.
7. The cross-dimensional phase-change device of claim 5, The two-dimensional spin Hall insulator comprises a two-dimensional ferroelectric phase, wherein the topological invariant of the two-dimensional ferroelectric phase is Z 2 =1; corresponding to a three-dimensional strong topological insulator, the topological invariant of the three-dimensional topological T' phase is (1; 000).
8. A method of manufacturing a half-metal material based cross-dimensional phase change device for obtaining a cross-dimensional phase change device according to any one of claims 1-7, characterized in that the method of manufacturing comprises: preparing a crystal flake of a semi-metal material by a chemical vapor deposition method or a mechanical stripping method, and transferring the crystal flake to the upper surface of a SiO 2 /Si substrate; preparing a metal electrode on the crystal flake by lithography and electron beam evaporation; And (3) performing electrical test on the trans-dimensional phase-change device, and verifying a resistance hysteresis loop by using a double-probe I-V test, wherein the critical voltage of the trans-dimensional structure phase change is +/-0.8- +/-1.6V.
9. A phase-change inducing method of a cross-dimensional phase-change device based on a semi-metallic material, the phase-change inducing method being used for inducing the cross-dimensional phase-change device according to any one of claims 1 to 7 to form a cross-dimensional structure phase-change reconstruction, the phase-change inducing method comprising: Applying positive external electric excitation to the metal electrode, and raising the local temperature of the semi-metal material layer to a critical point of cross-dimensional structure phase transition through the Joule thermal effect to trigger the transition from a two-dimensional ferroelectric phase to a three-dimensional topology T' phase; applying a reverse external electrical excitation to the metal electrode, and reversibly converting the three-dimensional topological T' phase into a two-dimensional ferroelectric phase by Peltier effect cooling, wherein The external electric excitation is voltage scanning, and the scanning voltage range is +/-1.0- +/-2.0V.
10. An application of a cross-dimension phase change device based on semi-metal material in a topological quantum device is characterized in that, The trans-dimensional phase change device is a trans-dimensional phase change device according to any one of claims 1-7 or the trans-dimensional phase change device is a trans-dimensional phase change device obtained according to the manufacturing method of claim 8; The cross-dimension phase change device realizes reversible switching between a high-resistance state and a low-resistance state through a resistance hysteresis loop; The cross-dimensional phase change device realizes the topology state regulation from the two-dimensional spin Hall insulator to the three-dimensional strong topology insulator through the cross-dimensional structure phase change.

Description

Cross-dimension phase change device based on semi-metal material, preparation method, phase change induction method and application Technical Field The invention relates to the technical field of topological quantum devices, in particular to a cross-dimension phase-change device based on a semi-metal material, a preparation method, a phase-change induction method and application. Background Phase change is one of the key means to regulate the electrical, optical and topological properties of materials. Conventional phase changes, such as the 2H-1T' phase change in molybdenum ditelluride (MoTe 2), typically occur in the same dimension (e.g., two-to-two), with atomic rearrangements limited to in-plane, and no change in the overall dimensions of the material can be achieved. In recent years, although research reports a trans-dimensional phenomenon such as the transition from titanium selenide (TiSe 2) to titanium diselenide (Ti 2Se9), such phase transition is often accompanied by chemical composition changes, and the process is usually irreversible, so that the application of the phase transition in functional devices (such as memory storage and logic switches) needing reversible operation is severely limited. The dimensions are used as basic physical properties of the material and directly influence the symmetry and the electronic structure of the material. The controllable and reversible cross-dimensional phase change (from two dimensions to three dimensions) is realized, and the method is hopeful to induce new physical property transitions which cannot be realized by conventional phase change, such as mapping and regulation of topological quantum states among different dimensions. However, how to realize the reversible cross-dimensional phase change and apply the reversible cross-dimensional phase change to a functional device on the premise of keeping the chemical composition of the material unchanged is still a core technical problem to be broken through in the field. A variety of stable two-dimensional phases are known to exist in topological semi-metallic materials represented by platinum dibismuth (PtBi 2), but the current research is limited to physical property regulation in two-dimensional phases, and the technical search for realizing new functions and quantum devices through cross-dimensional phase transition has not been involved. In view of this, a novel cross-dimensional phase change device based on semi-metallic materials, a preparation method, a phase change induction method and application are proposed to solve the above problems in whole or in part. Disclosure of Invention In order to solve at least one aspect of the problems and defects in the prior art, the embodiment of the invention provides a cross-dimensional phase change device based on a semi-metal material, a preparation method, a phase change induction method and application, wherein the cross-dimensional structural phase change between an equal component and reversible two-dimensional ferroelectric phase and a three-dimensional topological T ' phase is realized in the semi-metal material such as PtBi 2 by controlling the induction phase change, the phase change breaks through the dimensional limitation of the traditional phase change based on a definite atomic mechanism of ' intra-layer splitting-inter-layer reconstruction ', a ' hat ' -shaped resistor-voltage hysteresis loop is shown, the reversible and nonvolatile switching between a high-resistance state and a low-resistance state is realized, the ' dimension ' is taken as a parameter for driving the topological phase change, and the cross-dimensional topological phase change from a two-dimensional spin Hall insulator to a three-dimensional strong topological insulator is realized, so that a new dimension for topological physical property regulation is provided for the topological electronic field. The technical scheme is as follows: According to one aspect of the present invention, a cross-dimensional phase change device based on a semi-metallic material is provided. The cross-dimensional phase change device includes: A SiO 2/Si substrate; the semi-metal material layer is positioned on the upper surface of the SiO 2/Si substrate, and the initial state of the semi-metal material layer is a two-dimensional ferroelectric phase; a metal electrode in electrical contact with the semi-metal material layer, wherein The external electric excitation causes the semi-metal material layer to generate a phase change of a cross-dimensional structure with unchanged components and reversibility through the metal electrode, and the phase change is changed from a two-dimensional ferroelectric phase to a three-dimensional topological T' phase, and a resistance hysteresis loop is formed along with abrupt change of a resistance state. In some embodiments, in particular, the semi-metallic material is any one of PtBi 2、PdBi2 and NiBi 2, or any combination thereof, and the layer of semi-metallic mate